[1] Univ Uppsala Hosp, Dept Neurosci, SE-75185 Uppsala, Sweden
[2] Karolinska Inst, Inst Environm Med, Dept Epidemiol, S-10401 Stockholm, Sweden
[3] Karolinska Inst, Dept Clin Neurosci, Sect Personal Injury Prevent, Stockholm, Sweden
[4] Univ Toronto, Fac Med, Dept Publ Hlth Sci, Toronto, ON, Canada
[5] Univ Hlth Network, Toronto Western Hosp, Res Inst, Div Outcomes & Populat Hlth, Toronto, ON, Canada
[6] Univ Alberta, Dept Publ Hlth Sci, Alberta Ctr Injury Control & Res, Edmonton, AB, Canada